JPH09159282A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat exchanger of an auxiliary heat exchanger by a method wherein a vertical wall extending from the upper end of a can body down to a specified range is arranged at an inversion boundary part between the downstream area and the upper stream area of combustion exhaust gas of a can body to contain an auxiliary heat exchanger. SOLUTION: In such a state that a fan 5 is operated, a gas valve 61 is opened, a gas burner 3 is ignited, and combustion exhaust gas is fed to below. The sensitive heat of combustion exhaust gas is absorbed by a first straight pipe part ill of a main heat-exchanger 1a. After the lowering flow of combustion exhaust gas passing a main heat exchanger 1a flows to a second can body 2b, the flow is lowered to the lower part of a vertical wall by a vertical wall 4a. After the flow passes through a gap between the lower end of the vertical wall 4a and the bottom wall of the second can body 2b and is returned to a rise direction, it is raised to the exhaust cylinder 21 side and discharged. When combustion exhaust gas flowing in the second can body 2b passes a second straight pipe part 121 of an auxiliary heat exchanger 1b, temperature is lowered to a value lower than a dew point and drain is generated at the second straight pipe 121, and a latent heat in an mount equivalent to the generation amount of the drain is absorbed by the second straight pipe part 121.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchange device, and more particularly to a heat exchange device provided with a main heat exchanger for absorbing sensible heat of combustion exhaust and a sub heat exchanger for absorbing latent heat of the combustion exhaust. It is a thing.

[0002]

2. Description of the Related Art As a conventional heat exchange device, there is one shown in FIG. In this case, the gas burner (3) in the can body (2) is forcibly combusted by the air discharged from the fan (5) connected to the upper end of the can body (2), and the combustion exhaust is sent downward. It is the one. A main heat exchanger (1a) and a sub heat exchanger (1b) are arranged below the gas burner (3) in this order in a downward direction. Further, an exhaust pipe (21) is projectingly provided at the lower rear end of the body portion of the can body (2).

The combustion exhaust gas from the gas burner (3) passes through the main heat exchanger (1a) and the sub heat exchanger (1b) and then flows at the bottom of the can body (2). It is bent rearward in the horizontal direction and discharged from the exhaust tube (21) to the outside of the apparatus. Then, when the combustion exhaust passes through the main heat exchanger (1a), a plurality of heat exchange pipe sections (11) (11) constituting the main heat exchanger (1a) reveal the combustion exhaust. Heat is absorbed.
Further, when passing through the sub heat exchanger (1b), water vapor in the combustion exhaust gas is cooled to a dew point or lower to generate drainage,
The latent heat for that amount is the heat exchange pipe section (11) of the sub heat exchanger (1b).
It is absorbed in (11). In this case, since the latent heat is absorbed in addition to the sensible heat, the heat exchange efficiency is high.

However, the main heat exchanger is attached to the can body (2).
(1a) and the auxiliary heat exchanger (1b) are built in, and since the auxiliary heat exchanger (1b) for absorbing the latent heat is relatively large, the height of this heat exchange device is large. Will be things.

[0005]

Therefore, as shown in FIG. 8, a rectangular box-shaped second can body (2b) accommodating the sub heat exchanger (1b) is provided at the bottom of the heat exchange device. , This second can
First can body containing the main heat exchanger (1a) above (2b)
It is conceivable that the (2a) and the exhaust stack (21) are connected in parallel.

In this case, since the sub heat exchanger (1b) is provided at the bottom of the heat exchange device, the height of the heat exchange device can be suppressed as compared with the above-mentioned conventional technique. . Moreover, since the exhaust tube (21) extends above the second can body (2b), the depth of the heat exchange device can be suppressed. Therefore, the entire heat exchange device is downsized. On the other hand, the downward flow of the combustion exhaust gas from the main heat exchanger (1a) flows into the second can body (2b) and then reverses in the ascending direction in the second can body (2b). Then, it flows out from the second can body (2b) and rises in the exhaust stack (21).

However, when the flow of the combustion exhaust gas is reversed in the ascending direction, the flow is apt to be short-circuited, and the inside of the heat exchange pipe parts (11) and (11) of the sub heat exchanger (1b) is lowered. And the combustion exhaust does not reach the one on the side opposite to the rising region side of the combustion exhaust. As a result, the latent heat absorption from the heat exchange pipe parts (11) (11) becomes insufficient, and the heat exchange efficiency in the sub heat exchange area (1b) decreases. Therefore, the heat exchange efficiency of the entire heat exchange device is reduced.

According to the inventions of claims 1 to 3, "a main heat exchanger (1) for absorbing sensible heat of the combustion exhaust gas into a descending passage of the combustion exhaust gas.
a) is provided, a rectangular box-shaped can body accommodating the auxiliary heat exchanger (1b) for absorbing the latent heat of the combustion exhaust is provided below the can, and the combustion exhaust of the combustion exhaust is formed in the can. In a heat exchange device configured to reverse the flow in the ascending direction to raise the side of the main heat exchanger (1a), the problem is to improve the heat exchange efficiency in the sub heat exchanger (1b). And

[0009]

[Means for Solving the Problems] According to the means for solving the problems of the invention of claim 1, "In the can body accommodating the sub heat exchanger (1b), a reversal of a downflow region and a rising region of the combustion exhaust gas is performed. At the border,
A hanging wall (4a) extending downward from a certain range from the upper end of the can body is provided ”. The combustion exhaust gas that has flowed into the can body that houses the sub heat exchanger (1b) has a hanging wall (4a) that extends downward from a certain range from the upper end of the can body at the reversal boundary portion between the downflow region and the rising region. Guided by this hanging wall (4
After descending below a) and passing between the hanging wall (4a) and the bottom wall of the can body, it is reversed in the ascending direction. Therefore, in this structure, the combustion exhaust gas does not short-cut in the upper region of the can body, and the combustion gas is not generated in the lower region of the can body or in the end region opposite to the rising region side of the combustion exhaust gas. Exhaust reaches. That is, the combustion exhaust gas extends to almost the entire area of the can body.

Further, the cross section of the passage of the combustion exhaust gas has the hanging wall.
Since it is narrowed down by (4a), also in this point, the combustion exhaust easily spreads over the entire area of the combustion exhaust in the flow-down region side. According to a second aspect of the present invention, the sub heat exchanger (1b) extends at right angles to a plane including both the downflow region and the upflow region of the combustion exhaust gas in the can body. The heat exchange pipes (11) (11) are arranged side by side in the can body, and the heat exchange pipes (11) (11) in the downflow region are in the vicinity of the rising region side. , A plurality of exhaust guide plates (4b) (4b) extending in the vertical direction are provided ”.

Inside the can, a plurality of heat exchange pipe parts (11) (11) extending in a right angle with respect to a plane including both the downflow region and the upflow region of the combustion exhaust gas are arranged in parallel. Since a plurality of exhaust guide plates (4b) (4b) extending in the vertical direction are provided near the rising area side of the heat exchange pipe section (11) (11) in The descending flow is the exhaust guide plate (4b)
By (4b), reversal of the combustion exhaust gas to the rising region side is suppressed and guided downward. As a result, the downward flow of the combustion exhaust gas is in the vicinity of the exhaust guide plates (4b) (4b) and the heat exchange pipe section.
(11) Make sure to pass (11). Also, the exhaust guide plates (4b) (4
The downflow of the combustion exhaust gas easily reaches the heat exchange pipe portions (11) (11) located below b).

According to a third aspect of the present invention, the sub-heat exchanger (1b) is provided for a plurality of heat exchanges extending over a downflow region and a rising region of the combustion exhaust gas in the can body. Pipe (1
1) and (11) are arranged in parallel in the can body, and the heat exchange tube portions (11) and (11) penetrate a large number of fins (12) and (12). ' To do. In this configuration, the heat exchange pipe portion (11) (11) arranged in a direction extending across the downflow region and the rising region of the combustion exhaust gas penetrates a large number of fins (12) (12) group. Therefore, the downward flow of the combustion exhaust gas is guided downward along the fins (12) (12). That is,
The fins (12) (12) function similarly to the exhaust guide plates (4b) (4b) of the invention of claim 2.

Further, in addition to the heat exchange pipe parts (11) (11),
The heat of the combustion exhaust gas is also absorbed by the fins (12) (12).

[0014]

As described above, according to the first aspect of the invention, the combustion exhaust gas extends to substantially the entire area of the can body that houses the sub heat exchanger (1b). Therefore, the sub heat exchanger ( The non-heated portion of 1b) is eliminated, and the heat exchange efficiency of this sub heat exchanger (1b) is improved. In the invention of claim 2, the downflow of the combustion exhaust gas is in the vicinity of the exhaust guide plates (4b) (4b), and the heat exchange pipe portion (11) is provided.
Pass the (11) securely, and the heat exchange pipe section (11) (11) below it.
Also, since the combustion exhaust easily reaches, the non-heated portions of these heat exchange pipes (11) and (11) are eliminated, and the auxiliary heat exchanger (1
The heat exchange efficiency in b) is improved.

In the invention of claim 3, the fins (12) (12) are provided.
Functions as the exhaust guide plates (4b) and (4b), so that the heat exchange efficiency in the sub heat exchanger (1b) is improved. Further, in addition to the heat exchange pipe parts (11) and (11), the heat of the combustion exhaust gas is absorbed by the fins (12) and (12), so that the heat in the sub heat exchanger (1b) is absorbed. Exchange efficiency is further improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. [Embodiment 1] This Embodiment 1 is applied to a hot water heater. * Regarding the configuration of each part * This hot water heater is a main heat exchanger as shown in FIG. 1 and FIG.
A rectangular box-shaped second can body (2b) containing the auxiliary heat exchanger (1b) is connected below the first rectangular box-shaped can body (2a) containing (1a). In the can body (2b), an exhaust pipe (21) extending upward is connected to a portion of the can body (2b) protruding rearward from the first can body (2a).

A fan (5) is provided at the upper end of the first can body (2a).
And a gas burner (3) is arranged above the main heat exchanger (1a) in the first can body (2a). This gas burner (3) has a gas circuit (6) equipped with a gas valve (61).
Is supplied with gas. The first water pipe (110) constituting the main heat exchanger (1a) is a plurality of first water pipes (110) extending in the left-right direction of the first can body (2a) and penetrating the first fins (14) (14) group. 1 straight pipe part (111) (111) and the U-shaped first that connects the ends to each other
The bent tube portions (112) and (112) are formed in a meandering shape.
The first straight pipe section (111) (111) is installed between the left and right side walls of the first can body (2a), and the first bent pipe section (112) (11).
2) is exposed to the outside of the first can body (2a).

Second water pipe constituting the sub heat exchanger (1b)
(120) is formed in a meandering shape by a plurality of second straight pipe portions (121) (121) and second bent pipe portions (122) (122) similar to the main heat exchanger (1a). . The second straight pipe portions (121) (121) are installed between the left and right side walls of the second can body (2b), and the second bent pipe portions (122) (122) are the second cans. It is exposed outside the body (2b). And, the downstream end of the second water pipe (120) is
A supply pipe (16) for supplying heated water to the auxiliary heat exchanger (1b) is connected to the upstream end of the first water pipe (110) and is connected to the upstream end of the second water pipe (120). ) Is connected.

Further, the first can in the second can body (2b).
At the upper end between the can body (2a) and the exhaust pipe (21), a hanging wall (4a) extending in the middle of the area where the second straight pipe parts (121) (121) are arranged is continuously provided. There is. In addition, the hanging wall (4a) is the second can body (2
It is located in the left and right direction in b). * About the actual use of the water heater * With this, when the gas valve (61) is opened and the gas burner (3) is ignited with the fan (5) operating,
The gas burner (3) becomes in a combustion state, and the combustion exhaust gas is sent downward. Then, the main heat exchanger (1a) is heated by this combustion exhaust, and the sensible heat thereof is the main heat exchanger.
It is absorbed by the first straight pipe section (111) (111) of (1a).

Then, the downward flow of the combustion exhaust gas that has passed through the main heat exchanger (1a) flows into the second can body (2b) and then descends to the lower side by the hanging wall (4a). After passing between the lower end of the hanging wall (4a) and the bottom wall of the second can body (2b) and being turned upside down, it rises and flows out toward the exhaust pipe (21). Then, the combustion exhaust gas flowing into the second can body (2b) is transferred to the second straight pipe section (121) (12) of the sub heat exchanger (1b).
When passing through 1), the temperature of the combustion exhaust gas is lowered below the dew point to cause drainage in the second straight pipe portions (121) (121), and the latent heat corresponding to that is generated to the second straight pipe portion (121). ) (121) is absorbed. The drain attached to the sub heat exchanger (1b) is
It is dripped and discharged to the outside from a drain discharge pipe (22) continuously provided in the center of the bottom wall of the funnel-shaped second can body (2b).

[0021] In this structure, the downward flow of the combustion exhaust gas does not cause a shortcut due to the presence of the hanging wall (4a), and the second straight pipe section (121) (121) is positioned below. Also, the combustion exhaust reaches the one on the opposite side of the rising region of the combustion exhaust. That is, the second straight pipe section (121) (12
The combustion exhaust reaches all of 1). In the combustion state, the supply pipe (16) is connected to the second water pipe (120).
The water to be heated that has flowed into the first absorbs the latent heat and is heated up, and then flows into the first water pipe (110) to absorb the sensible heat and is further heated up to a high temperature hot water. Becomes This hot water is a hot water supply pipe connected to the downstream end of the first water flow pipe (110).
It is supplied to the bath etc. by (17).

In this embodiment, the sub heat exchanger (1b)
Is illustrated as having no fins, but as shown by the chain double-dashed line in FIG. 1, a large number of second fins (15) (15) orthogonal to the second straight pipe portions (121) (121) are provided. Provide the above hanging wall
Notches (151) and (151) may be provided in the portion corresponding to (4a). [Embodiment 2] In Embodiment 2, as shown in FIGS. 3 and 4, the second straight pipe portion (121) (121) of Embodiment 1 is used.
Is configured to penetrate a large number of second fins (15) (15) group. The hanging wall (4a) is not provided.

In the upper part of the middle of each second fin (15), a plurality of vertically elongated rectangular openings (13) (between the second straight pipe parts (121) (121) are provided. 13) is provided. A rectangular projecting piece (42) projecting from the second fin (15) is connected to a long side of each opening (13) opposite to the rising region side of the combustion exhaust gas. The size of this protruding piece (42) is
It is set to be slightly smaller than the opening (13). In this case, when the second fin (15) is manufactured, a U-shaped opening (19) as shown by the chain double-dashed line in FIG. 3 is punched out, and a part in the inner peripheral area is bent. When this is made to stand upright, this piece becomes the protruding piece (42). According to this method, the protruding piece (42) can be manufactured simultaneously with the second fin (15),
The productivity of this sub heat exchanger (1b) improves.

In this case, the downflow of the combustion exhaust gas is
The protruding pieces (42) (42) suppress the bending of the combustion exhaust gas toward the rising region side and guide the combustion exhaust gas downward. This allows
The downward flow of the combustion exhaust gas surely passes through the second straight pipe portions (121) (121) at upper and middle positions.
In addition, the protruding piece is guided by the downward guide of the combustion exhaust gas.
(42) The downflow of the combustion exhaust reliably reaches the second straight pipe sections (121) (121) in the region below (42).

In this case, the second straight pipe section (121) (121)
Is the heat exchange tube portion (11) (11) according to claim 1.
Further, the protruding pieces (42) (42) are the exhaust guide plates (4b) (4b) according to the above-mentioned claim 2. Instead of the protruding pieces (42) (42), as shown in FIG. 5, the second fins (15) (15) group extending along the second straight pipe portions (121) (121) Strip that penetrates through
The configuration may be provided with (43). In this case, the strip plate (43) is the exhaust guide plates (4b) (4b).

Further, as shown in FIG. 6, the second straight pipe section is provided.
(121) (121) may be arranged in a direction extending in the front-rear direction of the second can body (2b), and the protruding pieces (42) (42) may not be provided. In this case, the combustion exhaust gas is guided downward by the second fins (15) and (15) in the downflow region while being prevented from being bent toward the ascending region, and the second fins (15) and (15) are guided downward. After reaching the lower space, the air is inverted in this lower space in the ascending direction and ascends to the exhaust pipe (21) side. Even this one
As in the second embodiment, the downflow of the combustion exhaust reaches the second straight pipe parts (121) (121) in the downflow region of the combustion exhaust without fail. Needless to say, the space below the second fins (15) (15) is set to a size that does not hinder the upward reversal of the combustion exhaust gas.

In this case, the second fins (15) (15) are the fins (12) (12) described in claim 3.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat exchange device according to a first embodiment viewed from a side.

FIG. 2 is a cross-sectional view of main parts of the heat exchange device according to the first embodiment as seen from the front.

FIG. 3 is a cross-sectional view of a main part of the heat exchange device according to the second embodiment as viewed from the side.

FIG. 4 is a top view of a main part of the auxiliary heat exchanger (1b) according to the second embodiment.

FIG. 5 is a top view of a main part of a sub heat exchanger (1b) according to another embodiment.

FIG. 6 is a cross-sectional view of a main part of a heat exchange device according to another embodiment as viewed from the side.

FIG. 7 is a cross-sectional view of a conventional heat exchange device.

FIG. 8 is a sectional view of a main part of a conventional heat exchange device.

[Explanation of symbols]

 (1a) ・ ・ ・ Main heat exchanger (1b) ・ ・ ・ Sub heat exchanger (4a) ・ ・ ・ Hanging wall (11) ・ ・ ・ Heat exchange pipe section (4b) ・ ・ ・ Exhaust guide plate (12 )···fin

Claims (3)

[Claims] 1. A main heat exchanger (1a) for absorbing sensible heat of the combustion exhaust is provided in a descending passage of the combustion exhaust, and a sub-heat for absorbing latent heat of the combustion exhaust is provided below the main heat exchanger (1a). Exchanger
(1b) the rectangular box-shaped can body that accommodates is connected in series, the flow of the combustion exhaust gas in the can body is reversed in the ascending direction to raise the side of the main heat exchanger (1a) In the heat exchange device, the can body accommodating the auxiliary heat exchanger (1b) has a droop extending downward from a certain range from an upper end of the can body at an inversion boundary portion between a downflow region and an ascending region of the combustion exhaust gas. Heat exchange device with wall (4a). 2. A main heat exchanger (1a) for absorbing sensible heat of the combustion exhaust is provided in a descending passage of the combustion exhaust, and a sub-heat for absorbing latent heat of the combustion exhaust is provided below the main heat exchanger (1a). Exchanger
(1b) the rectangular box-shaped can body that accommodates is connected in series, the flow of the combustion exhaust gas in the can body is reversed in the ascending direction to raise the side of the main heat exchanger (1a) In the heat exchange device, the sub heat exchanger (1b) includes a plurality of heat exchange pipe portions (11) extending at right angles to a plane including both the downflow region and the upflow region of the combustion exhaust in the can body. ) (11) is arranged in parallel in the can body, the heat exchange pipe portion in the flow-down region (1
1) A heat exchange device, in which a plurality of exhaust guide plates (4b) (4b) extending in the vertical direction are provided in the vicinity of the rising area side of (11). 3. A main heat exchanger (1a) for absorbing the sensible heat of the combustion exhaust is provided in a descending passage of the combustion exhaust, and a sub-heat for absorbing the latent heat of the combustion exhaust is provided below the main heat exchanger (1a). Exchanger
(1b) the rectangular box-shaped can body that accommodates is connected in series, the flow of the combustion exhaust gas in the can body is reversed in the ascending direction to raise the side of the main heat exchanger (1a) In the heat exchange device, the sub heat exchanger (1b) has a plurality of heat exchange pipe portions (11) (11) extending over a downflow region and an ascending region of the combustion exhaust gas in the can body. A heat exchange device having a structure in which the heat exchange pipe parts (11) (11) penetrate a large number of fins (12) (12) while being arranged in parallel in the can body.